Pasadena, California, native Sophia Bush first wrote herself into America’s pop-culture lexicon by playing cheerleader-turned-fashion designer Brooke Davis on the popular TV drama One Tree Hill for nearly a decade. Now Bush is garnering acclaim as Detective Erin Lindsay on NBC’s hit police procedural Chicago P.D., recently renewed for a third season. The analytical, no-nonsense detective is not unlike the actress who plays her in her vocal advocacy for causes such as the environment and education. In a spirited conversation with friend and colleague Mariska Hargitay, Bush recently talked about the changing face of TV storytelling, her ideal Vegas weekend, and how she’s working every day for a brighter future.

Mariska Hargitay: Honey, how are you?Sophia Bush: I just got home and I feel like I’ve won the lottery.

MH: “Home” home, like LA home?
SB: Yeah.

MH: Good for you! So, sweet Sophia, let’s start at the beginning: Tell me when you first knew that you wanted to become an actor.
SB: It was honestly an accident. My junior high and high school had a series of arts requirements, and I put off my theater requirement until the last semester. I knew it would interfere with all my extracurricular activities. The second semester of my eighth-grade year, they said, “You have to take a theater class,” and I protested because I was on the volleyball team, and they said, “It doesn’t matter. You could have done this last semester, but you waited and now you have to do it.” We did a production of Our Town—

MH: Oh!
SB: Something just clicked, and I realized that my passion for English and my love of literature could be put into action. It rocked my world and I just thought, I get this.

MH: I have a similar story. I was an athlete. I met somebody and he was like, “You should go on auditions,” and I was like, “Nope, I’ve got a volleyball game; I’ve got a cross-country game.” It wasn’t until I did a play that I went, Hey, wait a minute. I like this. Doing sports as a young girl really teaches us how to strive for something. In so many ways, too, it makes you a better actor.
SB: Absolutely, because you have some understanding of the need to persevere. I get this question all the time about our schedules—people say, “What happens when you’re sick?”

MH: And you say, “Nobody cares.” [Laughs]
SB: If you’re sick, you come to work with a bucket and you deal with it.

MH: Speaking of work, tell me what you think it is about Chicago P.D. that the audiences connect to.
SB: First of all, we’re so lucky to be part of this larger wheelhouse that you’ve influenced and that Dick [Wolf] has been growing for so many years. Television has grown as an industry. When I was a little kid, there were only a handful of channels, and now there’s a thousand to choose from. That has widened avenues that we have for storytelling, because we’re not looking at shows the way we used to. I grew up watching reruns of Dragnet on Nick at Nite. There was a crime and then they solved it, and that was that. Now we’ve been given permission on the show to allow our heroes to be flawed. Are they bending the rules to service the law? Are they breaking the law? Do we root for them? Are we afraid of them? Nobody’s always playing perfect.

MH: What’s your favorite thing about playing Detective Lindsay?
SB: She’s not one of those bleeding hearts that sees the world and wants to fix it. She wants to fix the world because she was taken advantage of as a child, because she was recruited to work in a gang environment, because she was a drug addict, because she’s been at the lowest point and seen what one person who cares about you can do for you, and now she wants to give that to other people.

MH: And what initially drew you to it?
SB: I’d been on location doing [One Tree Hill] for nine years, and then I worked a season on a show in LA and was so excited to be home. I didn’t quite know what I wanted to do next, but I always wanted to work for Dick, and I always wanted to work with you. I get this call, and my agent said, “Dick Wolf is doing this show, and they really want to see you for the lead female, and it shoots in Chicago,” and I’m like, “No way. Chicago’s so cold, it’s so far away, I don’t know anybody there.... I’m not going.”

MH: [Laughs] But Dick Wolf has a pretty good record.
SB: I know. And they were like, “But Sophia, it’s literally two of the three criteria for a job you’ve ever wanted. You could just read it.” And I said, “All right.” I was protesting, but not much, because in the back of my head I was so excited. And you know what that feeling is like, when you read a script and from the first moment it gets its hooks in you? I just went, “Uh-oh.” [Laughs] I knew I was in trouble.

MH: You’ve said that Law & Order: SVU, which you starred in, obviously, in the crossovers, is your favorite show. What was that experience like? I want you to be honest. [Laughs]
SB: For so long, I talked about how all I would do on a day off was bingewatch SVU marathons and how Mariska Hargitay was just the coolest woman on TV. I was this shameless gusher. I was doing this as an actor on a show, so these words were being printed—it wasn’t, like, on my private Tumblr page. Then six or seven years ago, I was walking down the street in Soho, and I looked up, and it was like all the lights on Broadway started shining in my face—it became a weird sort of Wes Anderson film—and there you were, and I just blacked out. I know that I went up to you and that I probably babbled. I think you knew my brain was short-circuiting, and you touched my arm and said, “It’s so nice to meet you. I think your show is just great. Want to take a walk with me?” And I was like, “Sure.” What? And we just talked for 20 minutes, and it’s weird because now we text, we e-mail, we chat, we send each other stupid pictures, but I remember that day not understanding how to compute just how genuinely lovely you were.

MH: That’s so gracious, but it’s been such a pleasure getting to know you, working with you, and having you teach me how to tweet and Instagram. And your photos are amazing. This is a fun fact about Sophia Bush: She is such a great photographer. You wouldn’t even know she’s an actor, and she’s like, “Okay, stand over here.”
SB: Taking photos together now, it’s like, “Wow, I basically accosted this woman on the street in Soho, and now we’re working together—”

MH: And now you’re telling me where to stand for photos. [Laughs] But let’s talk about support: The environment is something that means a lot to you—you’ve done beach cleanups, marathons to benefit The Nature Conservancy. Tell me about conservation and why it’s so dear to you.
SB: I honestly think it’s a no-brainer, and some of that comes from growing up in Southern California—spending all my time as a kid exploring beaches and the sea and the mountains, and just realizing that we’re such a small part of this giant planet, yet we wreak the most havoc on it. When the president of the United States is saying that climate change poses a greater threat to American citizens than terrorism, people are finally opening their eyes and realizing that the world doesn’t exist for us to trample and use. I really hope that citizens will start to demand change both from the companies where they spend their money and the governments they elect to represent them.

MH: What are a couple of things you’d suggest to readers who want to protect the environment?
SB: It’s important to realize that every dollar you spend casts a vote. When you have to spend money, look at where it’s going. There’s actually a company that a friend of mine helped start called Conscious Commerce, where you can look up all kinds of conscious beauty products, gift items, fashion items. I switched over to a clean diesel [car] a couple of years ago, and it’s made a great impact on my life and saved me a ton of money in the process. I don’t use plastic bags anymore; I take my own bags to the grocery store. I try to drink bottled water that I bring from home in a glass bottle, but if I have to use plastic, I make sure I’m recycling. Buying my groceries at the farmers market on the weekend instead of buying produce that’s shipped using pesticides to stay fresh…. In the minutiae of our everyday, we have the chance to create change.

MH: It’s been beautiful to see how you’ve used your social media to get the message out there, and it says on your social media that you call yourself a “storyteller” and an “activist,” and “I believe a pencil can change the world.” How do you want to change the world?
SB: The notion of a pencil changing the world to me comes from all of my work with Pencils of Promise and really seeing that we have the capability to change the world by educating its children. I’d like to see us investing in education, in the environment. I’d like to see us treating one another like we’re all in this together. If every one of us really embraces that and says, “I should start with myself, then I can have a ripple effect in my universe,” that’s it.

Vegas: Local car dealers talk about how you wrote a Huffington Post op-ed in 2013 about the benefits of buying a diesel vehicle. What inspired that article?SB: I would love for clean-diesel vehicles to be a huge thing everywhere. It all ties back to being passionate about the environment and looking at ways to lower our fossil fuel consumption, looking at ways to create cleaner vehicles. Even when I was just looking for a car a couple of years ago, doing all the research and being able to sort of compare a regular gas option, a hybrid option, and a TDI—a clean diesel vehicle, and clean diesel won far and away—I just think it’s something we can do so easily, and I really wish that people were being given more options. This isn’t the kind of thing that we can wait on, taking care of the environment.

MH: Now, hold on—I heard you were at the iHeartRadio Music Festival in Vegas last September? I was there, and I did not know that you were there. [Laughs] Tell me about that, and how was your experience in Vegas?
SB: Oh, it was so much fun.

MH: How great is that city? Unlike any other place on the planet.
SB: It is. It’s so wild—kind of like Disneyland for grown-ups.

MH: I feel like it’s another planet. [Laughs]
SB: It is. [Laughs] I’ve only ever really been in Vegas for a weekend, and it’s usually to celebrate—we’ll do a bachelorette party, or a birthday.... We always just have a great time. Tao has always been lovely; Light has always been lovely.... Usually my MO in Vegas is, if I’m going for the weekend, I love to go out with my friends one night, and then love to hit the pool the next day, have a great meal, and see a show, and then head home on Sunday. I think that’s kind of the perfect mix. I’m not one of those people who can have a crazy night out two nights in a row. [Laughs]

MH: Yes, exactly.
SB: Two of my best friends and I, we flew in on Saturday morning. We spent a day lying by the pool and drinking smoothies and catching up. We saw so many of our favorite musicians play. I got to present Lorde, which was awesome ’cause I think she’s the coolest, and I was backstage with her before I went out to present her performance, and I’m watching her warm up, and I sort of forgot that she’s only 17. And then she gets out onstage, and she’s such a force, and it was really cool. I thought, We’re lucky we’ve got another really amazing generation of strong and incredible women who really have something to say and really care about their art.

MH: That’s exciting to watch. I feel like the younger generations are so much more self-possessed than we were. I remember thinking that even when I met you—I was like, God, if I knew what you knew when I was your age, I’d be a lot further along in the game, ’cause it’s exciting to see young women go after what we want and not have any sort of trepidation about it, but just be like: This is what I want, this is what I do, this is what I’m capable of, and I know I can do it, and I’m going to go after it. It’s fun to see people put sort of self-doubt and limitation behind them.
SB: I think it’s taken me forever to learn that. I feel like something sort of magical happens to women in their 30s, where suddenly you go, Oh! All the things that people told me—stop worrying and don’t doubt yourself and you’re doing great—oh, I see why they said that. And then I was looking at this girl and I was thinking, Look at how much she knows about everything.

MH: Already! [Laughs]
SB: Yeah, and it’s just going to get better for them.